package com.example.controller.other;

import cn.hutool.core.lang.UUID;
import com.example.result.JsonResult;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;

/**
 *   文件的上传与下载
 */
@RestController
@RequestMapping("/common")
@Slf4j
public class CommonController {
    @Value("${basePath}")
    private String basePath;

    //文件的上传
    @PostMapping("/upload")
    public JsonResult upload(MultipartFile file){
        //file是一个临时文件，需要转存到指定位置，否则本次请求完成后临时文件会删除
        log.info(file.toString());
        //原始文件名
        String originalFilename = file.getOriginalFilename();//abc.jpg
        //获取文件名称的后缀名
        String suffix = originalFilename.substring(originalFilename.lastIndexOf("."));
        //使用UUID重新生成文件名，防止文件名称重复造成文件覆盖,UUID+.文件后缀
        String fileName = UUID.randomUUID().toString() + suffix;

        //创建一个目录对象
        File dir = new File(basePath);
        //判断当前目录是否存在
        if(!dir.exists()){
            //目录不存在，需要创建
            dir.mkdirs();
        }

        try {
            //将临时文件转存到指定位置
            file.transferTo(new File(basePath + fileName));
            log.info("存储完毕-------------------");
        } catch (IOException e) {
            e.printStackTrace();
        }
        return new JsonResult(1,"上传成功",fileName);
    }
    //文件下载
    @GetMapping("/download")
    public void download(String name, HttpServletResponse response){
        if(name==null||name.equals("")){
            throw new RuntimeException("出错");
        }
        log.info("文件下载获取:"+name);
        try{
            FileInputStream inputStream = new FileInputStream(new File(basePath + name));
            ServletOutputStream outputStream = response.getOutputStream();
            response.setContentType("image/jpeg");

            int len=0;
            byte[] bytes = new byte[1024];
            while((len=inputStream.read(bytes))!=-1){
                outputStream.write(bytes,0,len);
                outputStream.flush();
            }
            //关闭资源
            inputStream.close();
            outputStream.close();
        }catch (IOException e){
            e.printStackTrace();
        }
    }
}
